中国光学十大进展:电子-声子耦合效应与激光波长拓展

China’s Top 10 Optical Breakthroughs:Electron-Phonon Coupling Effect and Laser Wavelength Extension

电子-声子耦合效应是拓展固体激光波长的基本原理之一。本文梳理了固体激光发展的历史,以电子-声子耦合导致的荧光展宽和可调谐激光器为主线,总结了色心激光晶体、过渡金属激光晶体、稀土激光晶体三类典型固体激光材料的发展历程和研究现状。近年来,基于多声子耦合机制的稀土激光晶体迅速发展,首次实现了突破荧光光谱的激光输出,极大地拓展了激光波长范围,为全固态可调谐激光器设计提供了新方案。同时,基于功能复合与交互作用规律,研制了一系列低成本、高集成的多声子耦合自倍频激光器,波长覆盖了青-绿-黄-橙-红光波段,满足了激光显示、激光医疗等领域的重要急需,对全固态激光技术的发展具有重要意义。

Electron-phonon coupling effect is an important physical phenomenon for laser wavelength extension in solidstate laser materials.This review summarized the history of tunable solid-state lasers,namely,color-center,transitionmetal,and rare-earth lasers,focusing on the spectral homogeneous broadening induced by the electron-phonon coupling effect.Recently,based on the multiphonon-coupling theory,an ultrabroadband laser emission far beyond the fluorescence spectrum was reported,thus greatly extending the available laser wavelengths.Moreover,various self-frequency doubling lasers were developed by combining the multiphonon-coupling and nonlinear-optical-conversion into one single crystal,thereby creating some low-cost and compact visible laser modules,covering the cyan-green-yellow-orange-red spectral range.These newly developed laser sources can meet the urgent demand of laser-based surgery and laser display applications,which can push and promote the rapid development of the all-solid-state laser technology.